JPS647577B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recess shaping method suitable for forming an uneven pattern on the surface of a resin molded product.

Normally, when a recess C is formed in a resin molded product A using a heating mold B, the molten resin rises to the surface by the volume of the recess to be molded, as shown in the first diagram, and the surface decoration of the resin molded product is improved. In order to avoid the protrusion D of the excess material that would damage the product, the resin molded product A' should be made hollow as shown in the second figure, or the inside should be made solid with a foamed resin layer a'. It was previously proposed that the depression of the concave portion C caused by the hot stamping die B should be allowed to escape within the hollow space or through the foamed resin layer a'. However, there are also products in which it is desired to form recesses in a resin molded product that is entirely formed solidly from the same resin as in the case shown in the first figure.

An object of the present invention is to provide a recess shaping method that can form recesses in such solid resin molded products without causing bulges.

That is, in the recess shaping method according to the present invention,
The surface recess is formed by forming a back recess in advance on the back surface of the resin molded product, and recessing the thick part until the back side becomes flatter than the front side corresponding to the molding position of the back recess. ing.

This will be explained below based on the embodiments shown in the third and fourth figures.

In the illustrated embodiment, the present invention is applied to a solid PVC extrusion molded product A to be used as a vehicle ornament, in which a high-frequency welder mold B is used to form surface recesses C corresponding to alphabetical characters.

In this resin molded product A, a backing recess E is formed in advance on the back side. The backing recess E is to provide relief for the depression of the thick wall part caused by the high-frequency welding mold B that will be added later, and in order to flatten the back side with the depression, it should be formed to have a volume that is approximately equal to or larger than the volume of the surface recess C that is to be recessed. do it. Although the volume can be secured by changing the depth even if it is relatively smaller than the shaped area of the surface concave portion C, it is possible to secure the volume by changing the depth, but it is possible to ensure the volume by changing the depth so that the area is approximately the same or larger so that the thick part can be easily depressed. It is preferable to take it.

The resin molded product A is processed so that the surface corresponding to the formation position of the backing recess E is pressed with a high-frequency welder mold B. As the welder mold B is pressed, the thick portion F gradually collapses and fills the backing recess E until the back side is flattened.
Therefore, depending on the shape of the surface recess C, even if the resin molded product A is solid, the excess material does not rise beyond the edge of the recess C, so that the recess C can be formed beautifully.

Note that the inner surface of the shaped recess C can be colored by painting, hot stamping, etc., or a board mark, a patch pen, etc. may be inserted and pasted thereon. In this case, each construction surface is located within the recess, so
It is possible to prevent them from being worn out or damaged.

As described above, according to the recess shaping method according to the present invention, it is possible to form recesses on the surface of a solid resin molded product without causing raised edges.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a normal recess forming state for a solid resin molded product, Fig. 2 is an explanatory diagram showing a recess forming state for a substantially hollow resin molded product, Fig. 3 a, b and FIGS. 4a and 4b are explanatory diagrams showing the process and state of forming a recess on a solid resin molded product according to the present invention. A: Resin molded product, B: High frequency welder mold, C:
Surface recess, E: Backless recess, F: Thick part.

Claims (1)

[Scope of Claims] 1. A backing recess is formed in advance on the back surface of a resin molded product, and the thicker part is pressed down from the front side corresponding to the molding position of the backing recess until the back side becomes substantially flat. A method for forming recesses on the surface of a resin molded product, characterized in that recesses are formed. 2. The recess forming method according to claim 1, wherein the backing recess has a volume that is substantially equal to or larger than the volume of the surface recess to be recessed. 3. The recess forming method according to claim 1, wherein the backing recess has an area substantially equal to or larger than the area of the surface recess to be recessed. 4. The recess shaping method according to claim 1, wherein the pressing depression is performed using a press die of a high-frequency welder.